I am a road warrior...The "crappy"
Walmart and Costco luggage more times than not will outlasts the premium name brand luggage. More expensive does not equal quality in luggage...longest lasting piece I ever had was a cheapie from Walmart. I have also bought my share of "premium" luggage that was absolute junk. Costco usually has a great selection
I prefer a semi rigid soft sided case. Gives you more room and flexibility and tend to be more durable when getting abused by the baggage handlers.
I used to be a four wheeler but went back to a larger two wheeled case. The four wheels are great for gliding around the airport floor, but they have smaller wheels and do not drag nearly as easily everywhere else. The larger the wheels, the easier it will roll. At times it felt like I was literally dragging the four wheelers. Kids tend to do better with the four wheelers however, less weight and balance they need to contend with. They can just push it along.
Size is not an issue for checked luggage, but they are sticklers on overweight down to the pound. Most carriers are 50lbs but double check your carrier. If you have a digital bathroom scale...step on, check your weight then step off...pick up luggage and step back onto scale to see what your luggage weight is by comparing the two weights.
If you think you may pick up some souvenirs and be at your weight and space limit, pack and travel with a small empty duffle bag or gym bag in your luggage. On the return trip you can pack that with dirty clothes that can be squished and check that as an additional bag to make space in your suitcase.
Whatever you get...make sure you add some decent luggage tags on a different handle than where the airline baggage tag will go (which is the top handle). If the airline tag comes off (which happens quite often) you bag will never be seen again if you do not have a luggage tag on it!
As other mentioned I am diehard Southwest fan for among other reasons each passenger gets TWO free checked bags. Round trip for a family the baggage fees can add up on other airlines.